5-hydroxy-2-keto-4, 5-diamino-4-ureidoimidazolidine aldehyde resins



S-HYDROXY-Z-KETO-4,5-DIAMlNO-4-UREIDO- IMIDAZOLIDINE ALDEHYDE RESINS No Drawing. Application October 7, 1950, Serial No. 189,053

Claims. 01. 260-675) This invention relates to new aminoplasts. More particularly, the invention rfelates to derivatives of S-hydroxy-2-keto-4,5-diamino-4-ureido-imidazolidine.

One object of this invention is to provide new aminoplasts.

A further object of this invention is to provide resinous derivatives of 5-hydroxy-2-keto-4,5-diamino-4-ureidoimidazolidine.

Another object is to provide 5-hydroxy-2-keto-4,5-diamino-4-ureido-imidazoilidine-aldehyde reaction products.

Still another object is to provide ethers of aldehyde-5- hydroxy-2-keto-4,5-diamino-4-ureido-imidazolidine reaction products.

These and other objects are attained by reacting 5-hydroxy-2-keto-4,5-diamino-4-ureido imidazolidine with aldehydes to form thermosetting resins which may be further modified by reaction with organic hydroxy compounds.

The following examples are given in illustration and are not intended as limitations on the scope of this invention. Where parts are mentioned, they are parts by weight.

Example I 5-hydroxy-2-keto-4,5-diamino-4-ureido imidazolidine was prepared by the oxidation of uric acid using potassium ferricyanide as an oxidizing agent according to the method described by Denicke in Liebigs Annalen, vol. 349, pp. 286-387. The oxidation product was dissolved in sodium hydroxide, the solution was filtered to remove impurities and the 5-hydroxy-2-keto-4,5-diamino-4-ureidoimidazolidine was precipitated with sulfuric acid. The precipitate was recovered by filtration and thoroughly washed to yield a white, crystalline material soluble in alkalies and insoluble in acids. On analysis, the product was found to be substantially pure 5-hydroxy-2-keto- 4,5-diamino-4-ureido-imidazolidine.

5-hydroxy-2-keto-4,5-diamino-4-ureido imidazolidine may be represented by the following formula:

Example 11 One mol of 5-hydroxy-2-keto-4,5-diamino-4-ureidoimidazolidine and four mols of formaldehyde in the form of a 37% solution in water were mixed with sulficient sodium hydroxide to attain and maintain a pH of from 8 to 9. The solution was then refluxed for about one hour at atmospheric pressure to obtain a solution of tetramethylol 5-hydroxy-2-keto-4,5-diamino-4-ureido-imidazolidine. The water was then removed by vacuum distillation to yield a slightly yellow, solid, brittle resin. The resin was soluble in alcohols, ketones and other common solvents.

Example III 100 parts of the dry resin made according to Example II were mixed dry with 100 parts of wood flour. The mixture was placed in a disc mold and cured at 120 C. for 10 minutes. The disc produced was hard, non-brittle Patented Jan. 18, 1955 and had a glossy surface. It was found that the disc produced had dimensions almost exactly those of the die used and that only infinitesimal shrinkage had occurred during the curing and cooling.

Example IV One mol of resin produced as shown in Example II was dissolved in six mols of methanol. 0.1 mol of formic acid in aqueous solution was added to the methanol solution which was then boiled under reflux at atmosphericpressure for about one hour to produce a methanol solution of the tetramethyl ether of tetramethylol S-hydroxy-Z- keto-4,5-diamino-4-ureido-imidazolidine. The excess methanol was removed by vacuum distillation to yield a slightly yellow, clear, liquid resin. The resin was soluble in water and organic solvents.

The ether resin could be cured to a solid, insoluble, infusible state by heating it at from C. to C. with or without the aid of an acid curing catalyst. It was compatible with alkyd resins to produce a high gloss coating composition having excellent weathering properties. It

could be applied to textiles and cured thereon without the use of acid catalysts, to shrinkproof and creaseproof the fabrics and to greatly diminish chlorine absorption of the fabrics during subsequent bleaching operations.

5-hydroxy-2-keto-4,5-diamino-4-ureido imidazolidine may be reacted with other aldehydes than the formaldehyde shown in Example 11 or a mixture of aldehydes may be used. Among the useful aldehydes are formaldehyde, acetaldehyde, benzaldehyde, cinnamaldehyde, crotonaldehyde, acrolein, methacrolein, furfural, etc. The amount of aldehyde which will react with the acid may vary from less than one mol to nine mols per mol of S-hydroxy- 2-keto-4,5-diamino-4-ureido-imidazolidine. An excess of aldehyde or aldehyde mixture beyond nine mols may be used, the excess being removed after the reaction is complete. The pH of the reaction medium may vary between about 8 and 9, sodium or other alkali metal hydroxide or ammonium hydroxide, or a suitable buffer being used to maintain the desired pH.

The resins thus obtained are slightly colored, fusible and soluble in alcohols, ketones, etc. They may be cured to an insoluble, infusible state by heating them with or without acid curing catalysts such as ethyl sulfonic acid at a temperature from about 100 C. to about 200 C. An especially advantageous feature of the resins is the almost complete absence of shrinkage during the curing and cooling operations. This feature permits the preparation of molded articles within exceptionally close tolerances for precision molding uses.

The resins may be mixed before molding with other curable aminoplasts such as aldehyde condensation products of urea, thiourea, dicyandiamide, guanidines, aminotriazines, e. g., melamines, etc. to decrease the shrinkage of such aminoplasts during molding operations. Likewise, mixtures of the imidazolidine may be mixed with one or more of these compounds and the mixture condensed simultaneously with the aldehyde.

Conventional additives such as fillers, dyes, pigments, lubricants, etc. may be mixed with the new resins prior to the molding operations.

As typified in Example IV, the aldehyde condensation products of 5-hydroxy-2-keto-4,5-diamino-4-ureido-imidazolidine may be further reacted with organic hydroxylcontaining bodies such as alcohols and phenols under acid conditions to provide ether resins for use in coating compositions alone or in combination with alkyd resins, and for use as textile or paper treating agents. Among the alcohols and phenols which may be used are methanol, ethanol, butanol, octanol, cetyl alcohol, stearyl alcohol, phenol, alkyl phenols, cresols, resorcinol, xylenols, allyl alcohol, crotyl alcohol, benzyl alcohol, cinnamyl alcohol, etc. A mixture of two or more alcohols may be used in which case an excess of the lower alcohol is usually reacted first and then the higher alcohol or phenol is reacted to exchange alcohol groups.

The amount of alcohol or phenol used may vary according to the amount of aldehyde reacted with the 5-hydroxy-2-keto-4,5-diamino-4-ureido-imidazolidine or may be substantially less than that amount. The maximum amount of alcohol or phenol which can be made to react is 9 mols per mol of nona-alkylol derivative of 5-hydroXy-2-keto-4,5-diamino .4 -.ureido -.imidazolidine. An excess of alcohol or phenol may be used.

According to another embodiment of this invention, 5whydroxya2rketo-4, 5-diamino-4-ureido-imidazolidine may be .reactedsimultaneously with an aldehyde and an alcohol .or phenol under acid conditions. toproduce ethers of the alkylol derivatives of 5'-hydroxy-Z-keto-4,'5-diamino- 4-ureido-imidazolidine.

The ether resins obtained by either method are compatible with alkyl resins and. are valuable for increasing the adhesion of alkyd resinsv to metal, glass, ceramics, etc. and in diminishing the tendency of the alkyd resins toshrink away 'from coated surfaces.

.1. A thermosettingvresin comprising'the condensation product of 5+hydroXy-2-keto-4,5-diamino-4 ureido-imidazolidine and an aldehyde.

They are also valu able for treating, textilesto shrinkproofand creaseproof 2. A thermosetting resin comprising the condensation product. .of .5.=hydroxy.-2.keto 4,.irdiamino-4-ureido-imidazolidine and formaldehyde 3. A thermosetting resin comprising the condensation product of 5-hydroxy-2-keto-4,5-diamino-4-ureido-imidazolidine, an aldehyde and'a'compound taken from the group consisting of alcohols and phenols.

4. Afthiermosetting .resin comprising the condensation product of 1 :mol of ,5-hydroxy12-keto-4,5-diamino-4- ureido-imidazolidine and 4 mols of formaldehyde.

'5. Athermosettingresin comprising the condensation product of *1 mol of 5-hydroxy-2-keto-4,5-diamino-4- ureido im-idazolidine, 4'mo1's of formaldehyde and 6 mols of methanol.

References (Iitedin the file of this patent UNITED STATES PATENTS D:Alelio Oct. 19, '1943 Walter July 4, 1950 OTHER REFERENCES 

1. A THERMOSETTING RESIN COMPRISING THE CONDENSATION PRODUCT OF 5-HYDROXY-2-KETO-4,5-DIAMINO-4-UREIDO-IMIDAZOLIDINE AND AN ALDEHYDE. 